1. Field of the Invention
This application relates generally to an improvement to the M16 rifle platforms by the addition of a set of mechanisms integrating an extra lateral, ambidextrous, frontal, non reciprocating charging handle, or sliding hand guard, acting in conjunction with a regulated gas piston direct drive system of easy installation, not requiring any machining or permanent modification of the standard M-16 receiver.
2. Background Prior Art
The use of the high pressure gasses inside the barrel of firearms to propel direct drive rods to force the unlocking of the bolt and allows its recoil is very old. AK 47, AK 74, AK (10)1; FAL, Galil, G3 H&K, FN 49, SKS, SVT (40) just to name a few. Recently several manufacturers like Bushmaster, Remington, Smith & Wesson, Rugger, Armalite, Heckler & Koch have incorporated the use of the direct drive gas systems to substitute the gas impingement system of the original M16 rifles and platforms alike, or manufactured retrofits, to substitute the original Gas Impingement System utilized in the popular M16 rifle and related platforms. The automatic cycle of the ejection of used shells, and reload of new rounds into the chamber is made possible by bringing into being an aged combination of pistons, cylinders, push rods, and springs utilizing the high pressure gasses to generate a strong rearwards displacement of the push rod, that in turn impacts a solid spot of the bolt carrier, inside the receiver, unlocking and displacing the bolt rearwards. Numerous nearly identical systems, now in fashion, perform in a similar manner and are being supplied as standard from the factory or as retrofit kits. That is what all of the formerly mentioned manufacturers have done as an attempt to present AN improved version of M16 and AR 15 platform rifles.
However, none of such direct drive gas piston systems takes advantage of mechanical elements already in place to go one significant step forward in solving the notorious disadvantage of the M16 and platforms alike which is associated with the uncomfortable rear charging action that must be performed by pulling straight back a T Charging Handle located at the rear of the receiver, resulting in a very uncomfortable maneuver, against all ergonomic principles, forcing the firer to decompose his firing posture to the extent that it may reveal the location to the enemy.
Replacing the OEM gas impingement system of the M-16 or AR-15 rifles platform by a direct drive gas piston system is not a new idea. Several attempts have been made to do so. It is well known to those who use this rifle, and in the industry that the M-16 is notorious for fouling and jamming due to the original design requiring the discharge gas be directed through a gas impingement tube into the bolt carrier to urge the bolt displacement to the rear in response to the firing of a cartridge and produce the expel of the spent shell and the reloading of a new round into the barrel rear end.
Most of the guns utilizing gases to assist in the opening of the bolt avoid the gas impingement system. AK 47, AK 74, AK (10)1; FAL, Galil, G3 H&K, FN 49, M1, M2 Carbine, M (14), SKS, BAR, FN SCAR, Remington ACR, just to name a few, utilize a combination of rods, and pistons, either being of short stroke or long stroke. However the majority of them have an external, reciprocating charging handle that can potentially harm the firer in its rearwards strong displacement when firing.
Others have developed systems to replace the OEM gas impingement system. Some require that significant portions of the rifle be modified or replaced, such as the barrel and parts within the receiver. These systems have obvious drawbacks. The cost of replacing the barrel and other parts is substantial and unnecessary. If machining is required to install the system, the user must send the rifle to a machinist or gunsmith to be modified, added time and expense to the process, and potentially, introducing error with each independent machining process.
Some manufacturers have designed systems that do not require the replacement of the barrel and are an improvement over the OEM and previous systems, such as the system manufactured by Land Warfare Resources Corporation (LWRC), Bushmaster, Adams, Smith & Wesson, Rugger, Remington Heckler & Koch H&K 416, DPMS, and Armalite. More over, Rock River also recently introduced a rifle having the Frontal Charging System and Direct Drive combination that works only with its proprietary design of an extended Upper receiver and cannot be incorporated to any existing M 16, AR 15 rifle platform. Adcor recently manufactured a rifle providing a combination of frontal charging handle and Direct Drive system, while maintaining the traditional rear charging handle. However, this improvement demands a profound change in the rifle design, and requires for its operation to work in cooperation with the main spring and a frontal extension of the upper receiver. It is not a simple addition to an existing M 16, AR 15 rifle platform that can be added as a retrofit kit, or a simple addition to the production of conventional rifles of that category.
Other important patents to mention are: U.S. Pat. No. 3,246,567, Miller; U.S. Pat. No. 4,244,273, Langerdorfet; U.S. Pat. No. 4,765,224, Morris; U.S. Pat. No. 5,351,598, Schutz, which have in common the utilization of a gas-piston direct drive, and one of them U.S. Pat. No. 6,634,274, Herring; even a structural protecting tube through which the actuating bar moves, and all of them keep the OEM T charging handle of the system, reason for which the problems associated with the rear charging operation by the OEM T handle subsist.
Generically all gas—piston direct drive systems utilize an actuator pneumatic combination of a cylinder, either static or mobile, receiving high pressure combustion gases from a piston, either static or mobile, and wherein the moving part displaces to impact a part of the bolt with sufficient energy to unlock the bolt and allow its opening. Interesting is to notice the very small differences in recently awarded patents with respect to gas-piston mechanisms utilized successfully since the 1940 s like the FN 49 rifle and then by the FAL rifle.
Almost identical is the Adams gas piston system in which the major improvement comes from the ability to extract, for cleaning, in a single piece, the rod and the cylinder, which are a single integral part in their design.
None of these existing systems provide any means to enable, as well, the manual charging action from the front of the rifle. Further more, none of these systems operate inside an easily attached structural tube to contain, guide, and protect the components of the system. None of the above mentioned combinations can be installed in existing M16 or AR15 rifle platforms as a retrofit kit of quick installation or removal without extensive irreversible modification to the receiver.